In a ruling that Electronic Frontier Foundation (EFF) staff attorney Hanni Fakhoury believes will be “cited a lot by EFF” and other privacy advocates, the Florida Supreme Court has said that law enforcement agencies must have a warrant to obtain cell phone location information that they need to track a user’s location in real time.

The decision by Florida’s highest court adds to the “growing chorus of courts” finding that location information is private, Fakhoury told SCMagazine.com Monday.

“It’s a great decision,” he said. “We think the court got it right.”

The case, Tracey vs. Florida made its way to the Supreme Court after police obtained cell tower data from a provider without a warrant to track the movements in real time of suspected drug dealer Alvin Tracey and used that information to illicit a conviction from a criminal court. Officers “obtained an order authorizing the installation of a ‘pen register’ and ‘trap and trace device’ as to Tracey’s cell phone,” which records outgoing and incoming telephone numbers, respectively, the Florida Supreme Court decision noted.

But later, without obtaining a warrant or providing additional “factual allegations,” the officers “used information provided by the cell phone service provider” under an earlier order. The information provided “included real time cell site location information given off by cell phones when calls are placed.”

Subsequent monitoring of Tracey and another man, Guipson Vilbon, led to the men’s arrest.

Tracey’s attorneys had asked the trial court to suppress evidence “derived from the real time cell site location information obtained” from Tracey’s phone, saying it required a warrant. The court denied the motion to suppress and, on appeal, the Fourth District Court of Appeal found no Fourth Amendment violation.

Citing Fourth Amendment protections as well as Supreme Court precedent in several cases, including Katz v. United States, the Florida Supreme Court quashed the Fourth District Court ruling, noting that many of smartphone “are ubiquitous and have become virtual extensions of many of the people using them for all manner of necessary and personal matters,” which makes a “phone’s movements its owner’s movements, often into clearly protected areas.”

Law enforcement agencies have, by and large, liberally applied their authority to search cell phones and track user locations and this is not their first time to have their hands slapped by a court in Florida. But last week’s ruling puts them on a shorter leash and the careful wording of the decision “extends to other devices like stingrays,” said Fakhoury, to track suspects via real-time cell phone location data without a warrant.

It will likely set the tone for future cases as well.

“Hopefully it will convince other state courts, federal courts and lawmakers” to follow suit, said the EFF lawyer, who called the Florida court ahead of the curve. “But, how that’s going to look on the ground, I don’t know.”